Transcript NATURE OF SCIENCE

Developing an
understanding of science
• What science is and what it is not.
• What science can do and what it cannot do.
• How science contributes to culture.
What is the Nature of the Processes
which Relate to Science ?
Is Science a process which:
1. can solve all kinds of problems and questions ?
What is your viewpoint??
A possible viewpoint you may hold
The scope of science is limited strictly to solving problems
about the natural world. Science is not properly equipped to
handle the supernatural realm (as such), nor the realm of
values and ethics (or religious beliefs).
Science is a process which:
2. can ignore rules ?
A possible viewpoint - Science must follow certain rules;
otherwise, it's not science (just as football/ice hockey, is not
football/ice hockey if the rules are not followed).
3. seeks the truth or facts ?
A possible viewpoint - The goal of science is to come as
close as we can to understanding the cause-effect realities
of the natural world. It's never "truth" or "facts". "Truth" and
"facts" can mean different things to different people.
WHAT !!
THE GOAL OF SCIENCE IS NOT ABOUT FACTS !!
WHAT DO WE TEACH IN SCIENCE LESSONS ???
This is a nice spiral, right?
Wrong... It's a set of independent circles
Science is a process which:
4. attempts to prove things ?
A possible viewpoint - The process of science, when properly
applied, actually attempts to disprove ideas (i.e. tentative
explanations)... a process called "testing", or "challenging". If
the idea survives testing, then it is stronger, and more likely an
accurate explanation.
5. can produce any kind of explanation ?
A possible viewpoint - Supernatural explanations cannot be
used, since they can never be disproved (supernatural forces,
by definition, do not predictably follow the laws of nature.
Whatever results occur in any test can be attributed to those
nebulous forces, effectively ending any further efforts to
explain).
Science is a process:
6. which produces certainties, or absolute facts ?
A possible viewpoint - Science is a process which can only
produce "possible" to "highly probable" explanations for
natural phenomena; these are never certainties. With new
information, tools, or approaches, earlier findings (theories, or
even facts) can be replaced by new findings.
7. for which one solution is as good as another ?
A possible explanation - In science, there is a rigorous
analysis and fair-test comparison of alternative explanations,
using discriminate criteria, e.g., confirmation by multiple
independent lines of evidence, leading to one "best" solution.
8. which can be relied on due to its total
objectivity and internal self-correction ?
A possible explanation - Science can be done poorly, just
like any other human endeavour. We are all fallible, some of us
make fewer mistakes than others, some observe better than
others, but we are still subjective in the end.
9. which is always used properly ?
A possible explanation - Unfortunately, science is all too
frequently misused. Because it works so well, there are those
who apply the name of science to their efforts to "prove" their
favourite cause, even if the rules of science are not followed.
Such causes are properly labelled "pseudosciences".
10. which is free from values, opinions or bias ?
A possible explanation - Scientists are people, and although
they follow rules and try to be objective, both in their
observations and interpretations, biases are still there.
Unconscious racial or gender bias, social status, source of
funding, political leanings can, and do, influence one's
perceptions and interpretations.
11. in which scientific theories are "tentative ideas"
or "hunches".
A possible explanation - The word "theory" is often used this
way in everyday conversation, but a theory in science refers to
a highly probable, well-tested, comprehensive explanation,
usually for a large collection of observations.
Aspects of the Nature of Science
Tentative
Scientific knowledge is subject to change with new
observations and with the reinterpretations of existing
observations. All other aspects of NOS provide
rationale for the tentativeness of scientific knowledge.
Empirical
Scientific knowledge is based on and/or derived
from observations of the natural world.
These are fine, but ……
A rabbit or a duck?
Illusions
• Do you see the face?
Or an Eskimo?
A waterfall,
but are you
sure ??
Does A or B
form the
straight line
extension of
line C ?
Aoccdrnig to rscheearch at Cmabrigde
Uinervtisy, it deosn't mttaer in waht oredr the
ltteers in a wrod are, the olny iprmoatnt tihng is
taht the frist and lsat ltteer be at the rghit pclae.
The rset can be a toatl mses and you can sitll
raed it wouthit a porbelm. Tihs is bcuseae the
huamn mnid deos not raed ervey lteter by istlef,
but the wrod as a wlohe.
Do you believe that the lines at the top
of the trapezia are the same length ?
Let us continue looking at aspects of
science
So far we have said that the Nature of
Science is such that it is:
•
•
Tentative
Empirical (based on, or derived from,
observation)
Five Additional Aspects of Science
Socially and culturally embedded
Science is a human endeavour and is influenced by the
society and culture in which it is practiced. The values of
the culture determine what and how science is
conducted, interpreted, accepted, and utilised.
Subjectivity
The development of questions, investigations, and
interpretations of data are filtered through the lens of
current accepted theories and laws. This is an
unavoidable subjectivity that allows science to progress
and remain consistent, yet also contributes to change
in science when previous evidence is examined from
the perspective of new knowledge.
Creative
Scientific knowledge is created from human imaginations and
logical reasoning. This creation is based on observations and
inferences of the natural world.
Laws and Theories
Theories and laws are different kinds of scientific knowledge.
Laws describe relationships, observed or perceived, of
phenomena in nature. Theories are inferred explanations for
natural phenomena and mechanisms for relationships among
natural phenomena. Hypotheses in science may lead to either
theories or laws with the accumulation of substantial supporting
evidence and acceptance in the scientific community.
Theories and laws do not progress into one and another.
They are distinctly and functionally different types of knowledge.
Observation and Inference
Science is based on both observation and
inference. Observations are gathered through
human senses or extensions of those senses.
Inferences are interpretations of those
observations. Perspectives of current science and
the scientist guide both observations and
inferences. Multiple perspectives contribute to
valid multiple interpretations of observations.
WOULD YOU AGREE THAT THIS IS AN
IMPORTANT MESSAGE FOR THE TEACHING
OF SCIENCE IN SCHOOL.
INFERENCE IS AN ESSENTIAL COMPONENT
OF SCHOOL SCIENCE.
Dispelling the Myths about Science
• Scientific Laws and other such ideas are absolute.
• Hypothesis is an educated guess.
• A General and Universal Scientific Method Exists.
• Science and its Methods can answer all Questions
Evidence accumulated carefully will result in sure
Knowledge.
• Science and Its Methods provide Absolute Proof.
• Science is Procedural more than Creative.
• Scientists are particularly objective.
• Experiments are the Principal route to Scientific
Knowledge.
• Hypotheses become Theories that in turn become
Laws.
• Scientific conclusions are reviewed for accuracy.
• Acceptance of new Scientific Knowledge is
straightforward.
• Science models represent reality.
• Science and technology are identical.
• Science is a solitary pursuit.
The Nature of Science in Science Education Rationales and Strategies
William F. McComas 1998 Kluwer Academic Publishers
Try the following ACTIVITIES
A 3- holed bottle experiment
• A simple enough experiment, but ….
• What hypotheses did this involve ?
• What observations were relevant ?
• What explanations were offered ?
The 3 holed bottle experiment
• This is sometimes called a discrepant
event as the reality is not as expected.
(if you think about it, the sun ‘moving’ across the sky is a
discrepant event).
• But what scientific question could initiate
the experiment?
• If matter is made of particles, how can
matter be stored in containers?
Observe what does actually
happen.
What explanation do you have for what happened?
You should be able to put forward at least one
explanation. Explanations from the group may not all
be the same.
Select one explanation which you like. Now
based on that possible explanation, predict
what will happen when the second hole is
uncovered.
Observe what actually did
happen.
Did the result match your prediction ?
If so, do you feel your prediction is good?
If NOT, it seems your prediction is not good.
Can you put forward another Prediction?
Now we have one more hole. Let us again
make a prediction about the outcome if we
uncover all 3 holes.
Let us look at some ACTIVITIES
related to ideas of research
question, hypothesis,
observation and deduction
Examining a cube
• Create a group of 2 persons
• Examine (but do not touch/move) the cube
placed on the table.
• Individually, from your inquisitive
observation, frame a question which
you would wish to ask about the cube ?
• Each person records their questions.
Exploring one question further –
what is written on the bottom, i.e.
hidden side ?
• In your group, discuss this question.
• Record your group predictions.
Justify your predictions with appropriate evidence.
(ANOTHER IMPORTANT STEP FOR THE
TEACHING OF SCIENCE)
• If you feel it is useful, your group may give
more than one justification.
• If you have more than one prediction,
identify the dominant hypothesis.
Examining another cube
• In your groups, examine (but do not
touch/move) the new cube placed on the
table.
• Put forward your predicted answer as to
what is on the hidden, bottom face of the
cube.
• Record your prediction(s).
Cube 2 - a further stage
• Carefully raise one corner of the cube so
that, with the use of a mirror, you can see
the number recorded in the top right
corner, OR the bottom left corner (but not
both !!)
• Modify your prediction as to what is written
on the bottom of the cube, if appropriate.
Teaching and Cube 2
Does cube 2 give us any insight into the teaching
of science ?
Does it suggest that we do not necessarily need to
observe everything and that we can make
calculated guesses from other observations ?
We can make inferences.
• If a gas is colourless and lighter than air, can we infer
it is probably hydrogen ?
• Or if a gas is known to be hydrogen, then can we infer
a balloon containing hydrogen will …..
A Quiz
Did the previous slides make
sense???
Which option would you choose
for the following questions about
science and technology ?
What to do?
On a sheet of paper write your preferred
response to each of the following 7 questions
as per the instructions given.
What is the purpose of this quiz ?
• Its purpose is to see how much there is general
agreement among the participants.
The Nature of Science and Technology
1.
Science is:
(a)
(b)
(c)
a study of fields such as biology, chemistry and physics.
carrying out experiments to solve problems of interest.
a systematic investigative process and the resulting
knowledge.
inventing and designing things.
finding and using knowledge to make this world a better
place.
a body of knowledge that explains the world around us.
exploring the unknown and discovering new things about
the world.
an organisation of people called scientists who have ideas
and techniques for discovering new knowledge.
do not know.
(d)
(e)
(f)
(g)
(h)
(i)
2. In your opinion, what does Science aim at ?
(a) To make sure that what has been discovered about
the world is really true.
(b) To understand, explain and interpret the continuing
change in nature and its characteristics.
(c) To discover, collect and group facts about nature.
(d) To find ways to make people’s lives better.
(e) Do not know.
3.
Why do you think Scientists do
Scientific Research ?
(a) To make new discoveries.
(b) To try out their explanations for why things happen.
(c) To make something which will help people.
(d) To collect data as much as possible, and to draw out
scientific laws from data.
(e) Do not know.
4.
Which of the following statements about
Scientific Knowledge match your
Understanding of Scientific Knowledge
(a) Scientific knowledge is a well-organised collection of
facts.
(b) Today’s scientific knowledge is based on scientific
perspectives, ideas and interpretations from the past.
(c) Today’s scientists have produced today’s scientific
knowledge.
(d) Scientific knowledge contains only statements that are
100% true.
(e) Do not understand the term ‘scientific knowledge’.
5. A Scientific Theory is :
(a) An idea about what will happen.
(b) A most appropriate interpretation and explanation
which has been approved by scientists.
(c) A fact which has been proved by many experiments.
(d) Do not know.
6. Technology is:
(a) The application of science to enhance life.
(b) Manufactured artefacts such as appliances, tools and
scientific instruments.
(c) The hardware, techniques, processes, people
associated with items such as tools, appliances and
scientific instruments.
(d) Inventing, designing, developing and testing things
such as appliances, tools and scientific instruments.
(e) Very similar to science.
(f)
The process of manufacturing and the underlying knowhow.
(g) Something else e.g. ?
7. Circle all the statements with which you agree:
(a) Technological innovations and/or development of science
bring about environmental problems such as pollution and
acid rain.
(b) Science and technology often makes our lives healthier,
easier, and more comfortable.
(c) The prosperity of the nation depends to a greater extent on
science and technology.
(d) Science and technology rarely do harm to our lives.
(e) We cannot solve all the problems which we are facing only
by the power of science and technology.
(f)
Because science, technology and society are independent
mutually, they do not affect each other.
(g) Science and technology affect society on the one hand,
society affects science and technology on the other hand.